Permanent expander for split-skirt pistons



Aug. 8, 1939. F, c.

PERMANENT EXPANDER Filed March 24, 1938 DALTON 2,168,601

FOB SPLIT SKIRT PISTONS 2 Sheets-Sheet 1 Ffederz'ck CDmZfdn Wok/4 Aug. 8, 1939. c. DALTON 2,168,601.

PERMANENT EXP ANDER FOR SPLXT SKIRT PISTONS Filed March 24, 1938 2 Sheeis-Sheet 2 Frederick 6. 17a ton WM c W I Patented Aug. 8, 1939 UNITED. STATES 2,168,601 PERMANENT EXPANDER FOR. SPLIT-SKIRT PISTO Frederick C. Dalton, Portland, reg., assignor of one-fourth to W. H. Darby, Salem, Oreg., and one-fourth to E. R. Dalton, Portland, Oreg.

Application March 24, 1938, Serial No. 197,911

Claims.

My invention relates particularly to the art of internal combustion engines and, more particularly, it deals with split skirt pistons.

Primarily, the invention has for an object to 6 provide means to adjust the piston upon collapse, or upon wear of the piston-skirt and cylinder walls.

Further, it is an object to provide such adjusting means as can be operated without removing the piston, or taking down the engine after it has been once installed.

Again, the invention has for its object ,to provvide a simple and efiective way of efiecting the adjustment by means of a tool inserted through a spark plug hole or other opening at the necessary place in the cylinder head of the engine.

Other objects will in part be obvious and in part be pointed out hereinafter.

To the attainment of the aforesaid objects and ends the invention still furtherresides in the" novel details of construction, combination and arrangement of parts, all of which will be first fully described in the following detailed description, and then be particularly pointed out in the appended claims, reference being had to the accompanying drawings, in which:

Fig. 1 is a section on the line I-l of Fig. 2, showing one embodiment of the invention. Fig. 2 is a section on the line 2-2 of Fig. 1. Fig. 3 isa cross section on the line 3--3 of Fig. 2; Fig. 4 is a top plan view of the piston shown in Figs. 1 to 3. a

Fig. 5 is a section on the line 5-5 of Fig. 6, showing another embodiment of the invention.

Fig. 6 is a section on the line 6--6 ofFi 5. Fig. '7 is a top plan view of the piston show in Figs. 5 and 6.

Fig. 8 is an inverted plan view of the same.

40 Fig. 9 is an enlarged detail view of a portion of the adjusting screw showing its conical split end. In the drawings in which like numbers indicate the same parts in all the figures, I is the head of the piston which has ring grooves 2; the skirt 3 is split at 4 and separated-from the head at 18 and joined thereto at Ill. The piston pin bosses are indicated by 5.

Projecting inwardly at each side of the split 4 is a lug 6. These lugs constitute a boss or guide.

in the form of the invention shown in Figs. 1 to 4,

" inclusive, is made integral with the head and land The screw I0 is threaded into the boss 8 which,

of the piston (see Fig. 2), the boss 8 being threaded at 9 for the purpose of receiving the screw.

The screw ID has a suitable tool receiving kerf or recess l6 at its upper end, while at its lower end it has a tapered or conical portionil that is 5 slit two ways at right angles, as at 12 (Figs. 2, 3 and 9), dividing such portion into four parts.

By providing the split l2 the tapered end is rendered resilient so as to permit normal expansion and contraction ofthe skirt due to temperature 19 changes without disturbing the setting of the screw ,and its adjustment eifect on the skirt. This screw is made of special steel that will cause the four parts to possess spring-tension when the end H is screwed down in the boss 6-6. 15

The boss 8, it should be noted, does not join to the skirt 4 but is formed integrally with the piston head and land only. 3

The head I at the upper end of the threaded boss 8 is counterbored and threaded as at l3, to 20 receive the screw plug l4 that serves as a lock for the adjusting screw l0 and has a tool receiving recess l5.

Should the piston wear, as it does in the course of several thousand miles, all one would have to 7 do is to take out screw II and turn down adjusting screw II) to the right tension desired. This can be done with a tool inserted down through D the spark plug hole, or some other opening at the necessary place in the Head of the engine, thereby saving much time and expense.

The same scheme can be applied to ordinary split-skirt pistons now in use by providing them with separate screw-carrying bosses 8 having -a flange 20 for securing the same to the under side of the piston head I by means of screws 2|, the boss being shaped to fit the piston, as shown, and having a portion '22 to underlie the land of the piston and project down into but out of contact with the skirt (see Fig. 6). 40

In Flgs. 5 to 8, inclusive, those parts which correspond to like parts in the preceding figures bear the same reference number plus the index letter a, so a repetition of the description thereof is thought to-be unnecessary.. In the embodiment shown in Figs.'5 to 8, inclusive, no lugs (such as 6'--6, in Fig. 2) are used, but the skirt at the slit 4 is drdlled or reamed, at 1, to lit the tapered end H of the screw which projects into the slit.

Adjustment in the latter form of the invention I ismade, in the same manner as for the first form,

- once the piston is assembled i-nthe engine.

Other modifications 01 the invention will be obvious to thoseskilled in the art.

I From the foregoing description, taken in con:

nection with the accompanying drawings. it is thought the construction, operation and advantages of the invention will be clear to those skilled in the art.

What I claim is:

1. In a split-skirt piston having piston pin bearings located within the confines of the skirt, means carried by the head of the piston and engaging the skirt portion of the-piston at a place intermediate the top and bottom ends of'the skirt for spreading the skirt, said means comprising a boss having a threaded bore extending at a downward and outward inclination to the head and axis 01 the piston and an' adjusting screw accessible through the head of the piston and having a tapered end to project into the split at an acute angle to the piston wall at a point in transverse alignment with the piston pin bearings.

2. In a split-skirt piston, means carried by the head of the piston and engaging the skirt portion of the piston at a place intermediate the ,top and bottom ends of the skirt for spreading the skirt, said means comprising a boss integral with I times.

. 3. In a split-skirt piston, means carried by the head of the piston and engaging the skirt portion of the piston at aplace intermediate the top and bottom ends oi the skirt for spreading the skirt, said means comprising a' boss integral with the head and land of the piston and having a downwardly and outwardly inclined threaded hole through the same andan adjusting screw in said.

hole, said screw having a split resilient tapered end to cooperate with the split portion of the piston as a spreading wedge and to permit the normal expansion and contraction of the skirt due to temperature changes without disturbing the setting of the screw and its adjustment effect on the skirt. 7

4. In a split-skirt piston, means carried by the I head of the piston and engaging the skirt portion of the piston at a place intermediate the top and bottom ends of the skirt for spreading the skirt, said means comprising a boss integral with the head and land of the piston and having a downwardly and outwardly inclined threaded hole through the same and an adjustingscrew in said hole, said screw having a resilient tapered end to cooperate with the split portion of the piston as a spreading wedge and to permit the normal expansion and contraction of the skirt due to temperature changes without disturbing the setting of the screw and its adjustment 'efiect on the skirt. i

5. In a split skirt 'piston having piston pin bearings, means'carried by the head of the piston and engaging the skirt portion of the piston only at a place adjacent a transverse plane normal to the axis of the piston and passing through the piston -pin bearings for spreading the skirt, said means comprising a boss having a threaded bore extending at an inclination to the axis of the piston and an adjusting screw accessible through the head of the piston for cooperation with the split portion ofthe skirt and havinga tapered end to project int i the split at an acute angle to the piston wall at a point in transverse alignment to the piston pin bearings, and means detachably securing said boss to the head and against the land or the piston.

6. In a split-skirt piston, means carried by the head of the piston and engaging the skirt portion of the piston for spreading the skirt, said means comprising a" boss having a threaded bore extending at an inclination to the axis of the piston and an adjusting screw accessible through the head of the piston and having a tapered split end for cooperation with the split portion of the skirt, the skirt portion of the piston having ad-- jacent the split a pair of spaced lugs constituting a boss having a recess to receive the tapered end 01 said screw.

7. In a split-skirt piston having piston pin bearings located intermediate the ends of the skirt, means carried by the, head of the piston and engaging the skirt portion of the piston only at a place in transverse alignment with the piston pin bearings for spreading the skirt, said means comprising a boss having a threaded bore extending at an inclination to the axis of the piston and an adjusting screw accessible through the head of the piston for cooperation with the split portion of the skirt, the skirt portion of the piston having adjacent the split a pair of spaced lugs constituting a boss having a recess to receive the end of said screw, said recess being shaped to fit the end of said screw and the end of said screw being tapered and springy.

8. In a split-skirt piston, means carried by the head of the piston and engaging the skirt portion of the piston for spreading the skirt, said means comprising a boss extending down into the skirt of the piston having a threaded bore extending at a downwardly and outwardly inclination to the head and axis of the piston and an adjusting screw accessible through the head of the piston for cooperation with the split portion of the skirt, the head of the piston having a threaded counterbore, and a screw plug closing said counterbore and acting as a lock for said screw, the axis of said screw plug being located at an angle to that of said adjusting screw and said screw plug being positioned to bear against the upper end of said adjusting screw.

9. In a piston, a head portion having a continuous peripheral wall provided with ring grooves, a vertically split skirt located below and spaced from the head portion, oppositely disposed connecting elements joining the head portion and the skirt and having piston pin bearings located within the skirt walls in a location intermediate the top and bottom edges of the skirt, a boss carried by the head portion, said boss having a downwardly and outwardly inclined threaded bore, a screw held in said bore and accessible through the top of the piston, said screw having a pointed end to engage in the split of the skirt at the level of the piston pin bearings, said screw having. provisions to allow expansion and contraction of the various parts due to usual heat changes without disturbing the normal setting and mechanical-expander-function of the screw.

10. In a piston a head portion having a continuous peripheral wall provided with ring grooves, a vertically split skirt located below and spaced from the head portion, oppositely disposed connecting elements joining the head portion and the skirt and having piston pin bearings located within the skirt walls in a location intermediate the top and bottom edges of the skirt, a boss carried by the head portion and projecting down be- 2,188,801 I I 4 3 low the top edge oi the skirt, said boss having a. having provisions to allow expansion and condownwardly and outwardly inclined threaded traction or the various parts due to usual heat bore, a screw held in said bore and accessible changes without disturbing the normal setting through the top of the piston, said screw having and mechanical-expander-function of the screw. 9. pointed end to engage in the split of the skirt at the level of the piston pin bearings, said screw FREDERICK C. DALTON. 

